Conventionally, a lamp unit has been known which includes a part called a rotary shade. A rotary shade has been conceived which includes a twisted end surface which extends around a rotating axis so as to connect different positions in relation to the direction of the rotating axis (see, e.g., WO 14/091919). The twisted end surface is a portion that is projected as a boundary of a non-illuminated area which is formed partially within a high beam pattern. In the lamp unit provided with such a rotary shade, a position of the twisted end surface to be projected changes in the direction of the rotating axis as the rotary shade rotates so that it is possible to change a position of a boundary of a non-illuminated area, that is, a position or a size of a non-illuminated area without performing a swivel control.